Field of the Invention
The present invention relates to a composition for transfecting an anti-tumor virus into a tumor cell using a cross-linked product of PEGylated magnetic nanoparticles and catechol-grafted poly-L-lysine when an external magnetic field is applied.
Discussion of Related Art
Successful cancer gene therapy requires a delivery system that is nontoxic, and can achieve efficient in vivo transduction and transgene expression. Adenovirus (Ad) serotype-5 has been widely used in clinical applications due to its high titer ability, high transduction efficiency in both dividing and non-dividing cells, and the absence of genomic integration-mediated mutagenesis. Several clinical trials have reported the successful use of locally injected Ads for cancer gene therapy. Ad-based cancer gene therapy has continued to develop with cancer cell-specific replicating oncolytic Ads that are far superior to conventional technologies. Oncolytic Ad has many advantages, including the ability to self-propagate, lyse infected cancer cells, and produce 1,000 to 10,000 copies of progeny per infected cell, thus causing secondary infection of neighboring cancer cells in a tumor. Therapeutic gene-inserted oncolytic Ads show high gene-delivery efficiency and potential antitumor efficacy, in vitro and in vivo. However, Ads are dependent on the coxsackievirus and adenovirus receptor (CAR) for target cell entry, limiting the clinical efficacy of Ad-mediated cancer gene therapy. Earlier studies have demonstrated that cells with low CAR expression show poor Ad infectivity. Thus, overcoming the transduction efficiency of Ads in CAR-negative tumors is a crucial step in improving the therapeutic efficacy of oncolytic Ads.
Currently, hybrid vectors that combine the advantages of both viral and non-viral components are available. One proposed strategy to overcome the limitations of Ads' CAR-dependence is to modify the Ad surface with a polymer that bypasses the need for CAR-mediated endocytosis. Modifying Ads with cationic polymers or lipids enhances Ad-mediated gene delivery. However, these strategies do not address targeted tumor-specific Ad-mediated gene delivery because injected polymer/lipid-modified Ads rapidly disseminate into surrounding non-target tissues.
Magnetic nanoparticles provide accelerated vector accumulation in target sites when directed with magnetic field-enforced delivery. This approach is customizable by adjusting particle size, surface charge density, and surface functionality with therapeutic drugs or genes, and results in enhanced cellular uptake and replication efficacy, and specific delivery to target tissues.
Coupling Ad viruses to polyethyleneimine (PEI)-coated super-paramagnetic iron oxide (Fe3O4) nanoparticles improves gene transfection efficiency when these vectors are directed by an external magnetic force (MGF). Considering the point that the usage of 25 kDa PEI is limited in vivo due to substantial cytotoxicity, magnetofection with PEI-coated superparamagnetic iron oxide nanoparticle-coated Ad can provide a strong platform for efficient and safe delivery of therapeutic genes. Moreover, the PEI coating on magnetic nanoparticles condenses anionic nucleotides such as plasmid DNA and siRNA into compact complexes, and facilitates their escape from endosomes via the proton sponge effect. Gene delivery mediated by magnetic nanoparticles exhibits higher transfection efficiency compared to conventional polyplex transfection. Park et al. (J. W. Park, K. H. Bae, C. Kim, T. G. Park, Clustered magnetite nanocrystals crosslinked with PEI for efficient siRNA delivery, Biomacromolecules 12 (2011) 457-465) disclosed that clustered, magnetized, PEI-encapsulated, super-paramagnetic Fe3O4 particles enhance magnetization properties and sustain super-paramagnetism, without exhibiting magnetic hysteresis. These particles induce faster sedimentation and greater accumulation within cells, and deliver drugs or genes rapidly under an MGF. In addition, PEG-coated, cross-linked, iron oxide nanoparticles (PCIONs) have been known to deliver plasmid DNA into mesenchymal stem cells efficiently in response to an external MGF.
The present disclosure is aimed to improve the therapeutic efficacy of oncolytic Ads in vitro and in vivo in combination with PCIONs.
Many papers and patent documents are referenced and citation thereof is marked throughout the present specification. The disclosures of which are incorporated herein by reference in its entirety to more clearly describe the level of the art to which the present application pertains and the content of the present disclosure.